std::basic_string::shrink_to_fit

 

C++

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Regular expressions library (C++11)

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Thread support library (C++11)

 

Strings library

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basic_string

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std::basic_string

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basic_string::basic_string

basic_string::operator=

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basic_string::begin basic_string::cbegin (C++11)

basic_string::end basic_string::cend (C++11)

basic_string::rbegin basic_string::crbegin (C++11)

basic_string::rend basic_string::crend (C++11)

Capacity

basic_string::empty

basic_string::size

basic_string::length

basic_string::max_size

basic_string::reserve

basic_string::capacity

basic_string::shrink_to_fit (C++11)

Operations

basic_string::clear

basic_string::insert

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basic_string::push_back

basic_string::pop_back (C++11)

basic_string::append

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basic_string::npos

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operator+

operator== operator!= operator< operator> operator<= operator>=

swap(std::basic_string)

operator<< operator>>

getline

stoi stol stoll (C++11) (C++11) (C++11)

stoul stoull (C++11) (C++11)

stof stod stold (C++11) (C++11) (C++11)

to_string (C++11)

to_wstring (C++11)

Helper classes

hash<std::string> hash<std::wstring> hash<std::u32string> hash<std::u16string> (C++11)

 

void shrink_to_fit();		(since C++11)

Requests the removal of unused capacity.

It is a non-binding request to reduce capacity to size. It depends on the implementation if the request is fulfilled.

Parameters

(none)

Return value

(none)

Complexity

Constant

Example

run this code

#include <iostream>
#include <string>
int main()
{
    std::string s;
    std::cout << "Default-constructed capacity is " << s.capacity() << '\n';
    s.resize(100);
    std::cout << "Capacity of a 100-element string is " << s.capacity() << '\n';
    s.clear();
    std::cout << "Capacity after clear() is " << s.capacity() << '\n';
    s.shrink_to_fit();
    std::cout << "Capacity after shrink_to_fit() is " << s.capacity() << '\n';
}

Output:

Default-constructed capacity is 0
Capacity of a 100-element string is 100
Capacity after clear() is 100
Capacity after shrink_to_fit() is 0

See also

size length	returns the number of characters (public member function)
capacity	returns the number of characters that can be held in currently allocated storage (public member function)